1. Field of the Invention
The invention relates to a reading apparatus for photoelectrically reading character information such as a document or the like and for providing its output to an eyesight handicapped person who confirms the output by tactile perception and, more particularly, to a reading apparatus for an eyesight handicapped apparatus for photoelectrically reading such character information and for converting its output into a vocal output:
2. Related Background Art
According to the research on actual conditions of February, 1987, by the Ministry of Public Welfare in Japan, the number of physically handicapped persons (ages: 18 years and higher) in Japan is equal to 2.40 million. Among them, the number of eyesight handicapped persons is equal to 0.37 million and occupies 12.7%. The number of eyesight handicapped persons who are employed as regular employees is equal to 17,000 in all of Japan and constituted only 5.5% of the entire number of eyesight handicapped persons.
One of the greatest handicaps suffered by the eyesight handicapped the inability to read printed or written characters, namely, what are called ink characters. Communication by characters is an indispensable element of social ink lief.
(1) The first example (OPTACON) of the reading apparatus
This reading apparatus has been realized by Dr. John G. Linvill of Stanford University of U.S.A., and has been commercially available from TSI Co., Ltd. by the name of "OPTACON" since 1971. "Optacon" stands for "OPtical to TActile CONverter (converting apparatus from the optical perception to the tactile perception)". The dimensions of the apparatus are set to a lateral width of 16 cm, a depth of 16 cm, and a height of 4.8 cm, and its weight is 840 grams. The apparatus is portable.
FIG. 8 shows a circuit block diagram of the above reading apparatus. The operation will now be described in accordance with FIG. 8.
A source 11 is constructed by a small electric bulb and a reflecting mirror (not shown). A document 5 is illuminated by an illumination light 101 from the light source 11. A camera unit 12 forms a document image which has been transmitted through a zoom lens (not shown) onto a small silicon photodiode called a silicon retina which functions as a retina of the eye and converts into an electrical signal. An optical magnification can be changed to a value of up to 2.5 times by changing the magnification of the zoom lens.
A processor 20 extracts only the signal representing characters or symbols from the electrical signal and sends it to a display 16. The display is also called a tactile board and has a total of 100 small holes comprising five columns and twenty rows. One pin is enclosed in each hole. When the electrical signal is sent from the processor 20 to the display (tactile board) 16, the head portions of some of the pins are ejected out of the holes and are vertically finely vibrated.
FIG. 9 is a diagram of the display (tactile board) of five columns and seven rows. In the diagram, a black dot ( ) indicates a state in which the head portion of the pin is ejected out from the hole to this side. A white dot (.smallcircle.) denotes that the pin is located at the inherent position.
By perceiving the pin pattern (pattern information formed with the pins) by the finger, a character " " can be recognized.
The black dot ( ) locating at a position of 5 the fifth row and the first column indicates noise which occurs due to the fouling of the paper surface, the deposition of the ink, or the like. An increase noises makes tactile perception difficult.
In case of a black character written on white paper, the head portions of only the pins corresponding to the black portion are ejected out and are vibrated, thereby propagating substantially the same pattern as that seen by the eyes to the finger. In this manner, the OPTACON can read not only the printed characters but also hand-written characters, a figure, a musical score, or the like, and can also examine a pattern of a cloth material or the like. The characters on the display can be also displayed on the tactile board by accessing a computer.
(2) The second example (OCR) of the reading apparatus
FIG. 10 shows a circuit block diagram of a second example. Its operation will now be described in accordance with FIG. 10.
The light source 11 is constructed by a fluorescent lamp and a reflecting mirror (not shown). The illumination light source 101 from the light 11 illuminates the document 5. The camera unit 12 forms a document image onto a small silicon photodiode array such as a CCD which functions as a retina of the eye and converts into an electrical signal. A processor 21 relates to a portion thereof to convert the electrical signal into a character code. A method of examining a correlation of features of a character or a pattern matching method is used as a converting method. The character code (electrical signal) is extracted and sent to an output unit 14. The output unit 14 generates the character code as electronic information outputted to the outside, thereby converting it into voice signal or braille points. As a reading apparatus of such a type, there is an apparatus only for use in English or an apparatus which can read Kanji (Chinese characters)/ Katakana mixed sentences of Japanese.
The reading apparatus for directly converting a character pattern into a pin pattern as shown in the first example first has the following disadvantages.
1) Since the apparatus depends on tactile perception, the difference between the capabilities of individuals is large.
2) The capability deteriorates due to fatigue.
3) The character pattern is not converted into the character code. Therefore, although patterns other than characters can be read, the ability to connect the apparatus to other information apparatus is poor.
The reading apparatus (OCR type) of the second example has the following disadvantages.
1) In case of a document in which characters and images exist, the recognition ratio is low and it is necessary to extract a character area therefrom. Since the character area is ordinarily extracted by the naked eye, it is necessary to collate it with an original sentence.
2) The collation with the original sentence (confirmation of the character area) cannot be performed by an eyesight handicapped person. Therefore, the help by a normal eyesight person is necessary, thereby causing the self-reliance of the handicapped person to be limited.